The supplementation practices of elite athletes in Singapore were studied using an anonymous questionnaire. Information was sought on not only the type of supplements used but also dosage, rationale for use, and other factors that might influence supplement use including selected demographic parameters and sources of information relating to supplements. Data was collected from 160 athletes across a spectrum of 30 sports. Use of supplements was widespread, with 77% of respondents acknowledging use of at least 1 product. Respondents ingested a total of 59 different supplements, with each athlete using on average 3.6 ± 0.3 different products. Sports drinks, caffeine, vitamin C, multivitamin/mineral supplements, and essence of chicken were some of the most commonly ingested products, confirming that while vitamin/mineral supplements are popular, sports supplements and traditional/herbal preparations were also well accepted. Respondents preferred to source information pertaining to supplements from “significant others” and other readily accessible sources. A small number of respondents acknowledged the use of International Olympic Committee (IOC) banned or restricted substances, highlighting the need for athletes to consult sports medicine professionals with specialist knowledge of dietary supplements in advance of initiating any supplementation regime.
Gary Slater, Benedict Tan and Kong Chuan Teh
Reid Reale, Gary Slater and Louise M. Burke
It is common for athletes in weight-category sports to try to gain a theoretical advantage by competing in weight divisions that are lower than their day-to-day body mass (BM). Weight loss is achieved not only through chronic strategies (body-fat losses) but also through acute manipulations before weigh-in (“making weight”). Both have performance implications. This review focuses on Olympic combat sports, noting that the varied nature of regulations surrounding the weigh-in procedures, weight requirements, and recovery opportunities in these sports provide opportunity for a wider discussion of factors that can be applied to other weight-category sports. The authors summarize previous literature that has examined the performance effects of weightmaking practices before investigating the physiological nature of these BM losses. Practical recommendations in the form of a decision tree are provided to guide the achievement of acute BM loss while minimizing performance decrements.
Mitchell Naughton, Joanna Miller and Gary J. Slater
Athletes involved in contact sports are habitually exposed to skeletal-muscle damage in their training and performance environments. This often leads to exercise-induced muscle damage (EIMD) resulting from repeated eccentric and/or high-intensity exercise and to impact-induced muscle damage (IIMD) resulting from collisions with opponents and the playing surface. While EIMD has been an area of extensive investigation, IIMD has received comparatively little research, with the magnitude and time frame of alterations following IIMD not presently well understood. It is currently thought that EIMD results from an overload of mechanical stress that causes ultrastructural damage to the cellular membrane constituents. Damage leads to compromised ability to produce force, which manifests immediately and persists for up to 14 d following exercise exposure. IIMD has been implicated in attenuated neuromuscular performance and recovery and in inflammatory processes, although the underlying course over time remains unclear. Exposure to EIMD leads to an adaptation to subsequent exposures, a phenomenon known as the repeated-bout effect. An analogous adaptation has been suggested to occur following IIMD; however, to date, this contention remains equivocal. While a considerable body of research has explored the efficacy of recovery strategies following EIMD, strategies promoting recovery from IIMD are limited to investigations using animal contusion models. Strategies such as cryotherapy and antioxidant supplementation that focus on attenuating the secondary inflammatory response may provide additional benefit in IIMD and are explored herein. Further research is required to first establish a model of generating IIMD and then explore broader areas around IIMD in athletic populations.
Reid Reale, Gary Slater and Louise M. Burke
Purpose: Combat sport athletes undertake chronic and rapid weight loss (RWL) practices to qualify for weight divisions lower than their training weight. Variation between sports in the prevalence, methods, and magnitude of weight loss as well as recovery practices may be influenced by factors including competition level and culture. Differences in methodologies of previous research in combat sports make direct comparisons difficult; thus, this study aimed to examine weight loss practices among all Olympic combat sports in Australia, using standardized methodology. Methods: High-caliber competitors in wrestling, boxing, judo, and taekwondo (n = 260) at Australian competitions were surveyed using a validated tool that provides quantification of how extreme an athlete’s weight loss practices are: the rapid weight loss score (RWLS). Additional qualitative and quantitative survey data were also collected. Results: Neither sport, sex, nor weight division group had an effect on RWLS; however, a significant effect of athlete caliber was detected (F 2,215 = 4.953, mean square error = 4.757, P = .00792). Differences between sports were also evident for most weight ever lost in order to compete (H = 19.92, P = .0002), age at which weight cutting began (H = 16.34, P = .001), and selected methods/patterns of RWL (P < .001). Weight cycling between competitions was common among all sports as were influences on athlete’s behaviors. Conclusions: Although many similarities in weight loss practices and experiences exist between combat sports, specific differences were evident. Nuanced, context/culturally specific guidelines should be devised to assist fighters’ in optimizing performance while minimizing health implications.
Gregory Shaw, Gary Slater and Louise M. Burke
Thirty nine elite Australian swimmers (13 AIS, 26 OTHER) completed a standardized questionnaire regarding their supplement use during a pre competition camp. The data were compared with a similar study conducted 11 years earlier (11 AIS, 23 OTHER) and framed around the classification system of the Sport Supplement Program of the Australian Institute of Sport. The prevalence of supplement use remained constant over time (2009: 97%, 1998: 100%). However, the current swimmers used a greater number of dietary supplements (9.2 ± 3.7 and 5.9 ± 2.9; p = .001), accounted for by an increase in the reported use of supplements with a greater evidence base (Sports Foods, Ergogenics, and Group B supplements). In contrast, fewer supplements considered less reputable (Group C and D) were reported by the 2009 cohort (0.7 ± 1.0 and 1.6 ± 1.3; p = .003). AIS swimmers reported a greater use of Ergogenics (4.3 ± 1.8 and 3.1 ± 1.7; p = .002), and less use of Group C and D supplements overall (0.8 ± 1.2 and 1.3 ± 1.2; p = .012), which was explained primarily by a smaller number of these supplements reported by the 2009 group (1998 AIS: 1.5 ± 1.4, 2009 AIS: 0.2 ± 0.6; p = .004). Although the prevalence of supplement use has not changed over time, there has been a significant increase in the number and type of products they are using. The potential that these changes can be attributed to a Sports Supplement Program merit investigation.
Gary J. Slater, Jennifer Sygo and Majke Jorgensen
Although sprint athletes are assumed to primarily be interested in promoting muscle hypertrophy, it is the ability to generate explosive muscle power, optimization of power-to-weight ratio, and enhancement of anaerobic energy generation that are key outcomes of sprint training. This reflects the physique of track sprinters, being characterized as ecto-mesomorphs. Although there is little contemporary data on sprinters dietary habits, given their moderate energy requirements relative to body mass, a carbohydrate intake within the range of 3–6 g·kg−1·day−1 appears reasonable, while ensuring carbohydrate availability is optimized around training. Similarly, although protein needs may be twice general population recommendations, sprint athletes should consume meals containing ∼0.4 g/kg high biological value protein (i.e., easily digested, rich in essential amino acids) every 3–5 hr. Despite the short duration of competitions and relative long-recovery periods between races, nutrition still plays an important role in sprint performance. As energy expenditure moderates during competition, so too should intake of energy and macronutrients to prevent unwanted weight gain. Further adjustments in macronutrient intake may be warranted among athletes contemplating optimization of power-to-weight ratio through reductions in body fat prior to the competitive season. Other novel acute methods of weight loss have also been proposed to enhance power-to-weight ratio, but their implementation should only be considered under professional guidance. Given the metabolic demands of sprinting, a few supplements may be of benefit to athletes in training and/or competition. Their use in competition should be preceded with trialing in training to confirm tolerance and perceived ergogenic potential.
Gregory Shaw, Gary Slater and Louise M. Burke
This study examined the influence the Australian Institute of Sport (AIS) Sport Supplement Program had on supplement practices of elite Australian swimmers, comparing those guided by the Program with others in the same national team. Thirty-nine elite swimmers (13 AIS, 26 Other; 20 female, 19 male; age 21.8 ± 3.3 y) completed a questionnaire investigating supplement use. Ninety-seven percent of swimmers reported taking supplements or sports foods over the preceding 12 months. AIS swimmers reported using more total brands (p = .02) and supplements considered Ergogenic (p = .001) than Other swimmers who used more supplements considered to be lacking scientific support (p = .028). Swimmers rated the risk of a negative outcome from the use of supplements available in Australia (Mdn = 3.0) as less than the risk of supplements from international sources (Mdn = 4.0; p < .001). AIS swimmers were more likely to report dietitians (p < .001) and sports physicians (p = .017) as advisors of their supplement use. Other swimmers more frequently reported fellow athletes as a source of supplement advice (p = .03). AIS swimmers sourced a greater percentage of their supplements from an organized program (94 ± 16%) compared with Other (40 ± 32%; p < .001) who sourced a greater percentage (30 ± 30%) of their dietary supplements from supermarkets. These findings suggest that swimmers influenced by this sport supplement program more frequently use supplements that are recommended by allied health trained individuals, classified as evidence based and provided by the program.
Kristen MacKenzie, Gary Slater, Neil King and Nuala Byrne
Evidence suggests that increasing protein distribution may be desirable to promote muscle protein synthesis (MPS) in combination with resistance exercise. However, there is a threshold above which additional protein consumption has limited benefit for MPS and may promote protein loss due to increased oxidation. This study aimed to measure daily protein intake and protein distribution in a cohort of rugby players. Twenty-five developing elite rugby union athletes (20.5 ± 2.3 years, 100.2 ± 13.3 kg, 184.4 ± 7.4 cm) were assessed at the start and end of a rugby preseason. Using a 7-day food diary the reported daily protein intake was 2.2 ± 0.7 g·kg·day-1 which exceeds daily recommendations. The reported carbohydrate intake was 3.6 ± 1.3 g·kg·day-1 which may reflect a suboptimal intake or dietary underreporting. In general, the rugby athletes were regularly consuming more than 20 g of protein; 3.8 ± 0.9 times per day (68 ± 18% of eating occasions). In addition to documenting current dietary intakes, an excess protein estimation score was calculated to determine how frequently the rugby athletes consumed protein above a known effective dose with a margin of error. 2.0 ± 0.9 eating occasions contained protein in excess of doses (20 g) known to promote MPS. Therefore, it is currently unclear whether the consumption of regular large doses of protein will benefit rugby athletes via increasing protein distribution, or whether high protein intakes may have unintended effects including a reduction in carbohydrate and/or energy intake.
Mark R. McKean, Gary Slater, Florin Oprescu and Brendan J. Burkett
Australia has approximately 26,000 registered exercise professionals (REP), in comparison with 3,379 accredited practicing dietitians (APD). The REP workforce has the potential to reach more than 10% of the Australian population but there is limited data on their educational background and professional behaviors with regards to nutritional counseling of clients. The purpose of this research was to determine if REPs are working within their scope of practice and if their qualifications align with their practice, specifically as it relates to nutrition advice. Using a cross sectional descriptive study design, a self-administered online survey of REPs was conducted over 5 months. REPs were recruited through electronic and social media using a snowballing technique. The study focused on education, nutrition advice, and sources of information. A total of 286 respondents completed the survey, including 13 with tertiary dietetic qualifications i.e., APDs. The nationally recognized industry Certificate III/IV in Fitness was the most common qualification. The majority of REPs responding (88%) were working outside of their professional scope of practice, offering individual nutrition advice to clients across fitness and medical issues. This was despite 40% of REPs undertaking no further training in nutrition since graduating, and primarily basing advice on use of readily accessible sources of nutrition information. It is recommended the nutrition advice provided to REPs during training be limited to general nonmedical nutrition information in accordance with nationally endorsed evidence based guidelines and that issues pertaining to scope of practice be addressed with onward referral to other health professionals be advocated.
Chin Han Lew, Gary Slater, Gobinathan Nair and Michelle Miller
This study investigated the relationship between changes in upon-waking body mass (BM) and changes in urine specific gravity (Usg) and urine color (Ucol) from 1 day to the next. Throughout the 5-day investigation, healthy adolescent Singaporean athletes (n = 66) had their upon-waking, bladder-voided BM measured. A small aliquot of the first bladder void each day was collected and analyzed for Usg and Ucol, the latter by both an investigator (IUcol) and individual participants (SUcol). Results revealed a significant inverse relationship between changes in BM and changes in Usg (p = .003) and Ucol (p = .001). On average, Usg and Ucol changed by ~0.003 units and ~1 color (across a 9-unit scale), respectively, with every 1% change in BM from 1 day to the next. There was a stronger relationship between Usg and IUcol (r = .82, p < .001) than between Usg and SUcol (r = .60, p < .001). These results suggest that the degree of fluid deficit may be predicted from the Usg measurements among moderately hypohydrated athletes. In addition, training athletes to interpret and use the Ucol chart is recommended.